If you're making use of mathematical formulas you may need to find the powers of some numbers (for example : 3 to the power of 5 or something). The function to be used if pow( )
Syntax :     pow (base, exponent);
Header file needed : #include<cmath>     // if your compiler is an old one then type #include<math.h>
The function will return the answer, base raised to the exponent power.

I mentioned earlier that using cin you cannot get an input of spaces (i.e. when the compiler encounters a space character it will stop the input with that. Refer Q & A section for the details).
You can use the gets function to solve the problem
Syntax :     gets (char array name where you want to store the string);
Header file needed : #include<cstdio>      // if your compiler is an old one then type #include<stdio.h>
Characters are read till a new line is received.